Appendix B. Design Review Checklists
for Power Systems and Power Supplies

RELIABILITY CHECKLIST

Component Level

Have component derating guidelines been observed?

What is the failure history of this item?

Is the item critical; i.e., would its failure result in system failure?

What are the item's possible modes of failure?

What steps have been taken in the item's application or system design to
eliminate or minimize the effects of these modes of failure?

Is it possible to introduce the concepts of redundancy and/or use the item
at derated performance levels?

What is known about its storage life, operating time or cycles; i.e., how
much time or cycles, operating and nonoperating, may be accumulated without
significantly degrading its reliability?

If the component is newly developed, what are its critical weaknesses, and
what provision has been made in the design so that modifications can be made
at the earliest possible time if these or other weaknesses show up in testing?

Is it physically and functionally compatible with its neighboring
components; i.e., will the physical location affect its performance or
reliability?

Are any unusual quality control or vendor problems expected?

Circuit/Assembly Level

Does the item perform more than one function?

Have critical components been identified?

If an established design, is it being used as in previously experienced
environments and at normal operating levels?

Has the item been designed as simply as possible; i.e., have human factors
been considered to prevent errors such as reversed wiring or other
misassembly?

Have physical features which might adversely affect performance or
reliability been taken into account; e.g., are there any sharp comers which
might damage components or cause wiring insulation failure?

How might the design be modified to improve reliability, and what effect
would the modification have on such factors as performance, cost, weight,
availability, schedules, maintainability, etc.?

Has the item or system been designed for ease of production, assembly,
maintenance and inspection?

Have handling, transportation, packaging and environments other than the
specified operational environments been taken into account?

Have worst-case effects of tolerance buildup been considered?

Would any component failure modes cause secondary failure; i.e., cause
damage or failure of other components?

Has the regulation control loop been analyzed and tested for adequate gain
and phase margin for all operating conditions?